Adjusting the seat post cam action mechanism
The action of the cam squ eezes the seat co llar aroun
d the seat post to ho ld the seat post securely in place. The amount of
clamping force is controlled by the tension adjusting nut. Turning the tension adjusting nut clockwise while keeping the cam lever
from rotating increases clamping force; tu rning it counterclockwise while keeping the cam lever from rot ating reduces clamping
force. Less than half a turn of the tension adjusting nut can make the difference between safe and unsafe clamping force.
WARNING: The full force of the cam a ction is n eeded to clamp the seat p ost securely. Holding the nut with one
hand and turn
ing the lever like a wing nut with the other hand until everything is as tight as you can get it will not
clamp the seat post safely.
WARNING: If you can fully close the cam lever without wrapping your fingers around the seat post or a frame tube
for leverage, a nd the lever does not le ave a clear imprint i n the palm of y our hand, t he tension is insufficient.
Open the lever; turn the tension adjusting nut clockwise a quarter turn; then try again.
C. Brakes
There are three gener al types of bicycle brakes: rim brakes, which operate by squeezing the wheel rim between two brake
pads; disc brakes, which operate by squeezing a hub-mounted disc between two brake pads; and internal hub brakes. All three
can be operated by way of a handlebar mounted lever. On some models of bicycle, the internal hub brake is operated by pedaling
backwards. This is called a Coaster Brake and is described in Appendix C.
WARNING:
1. Riding with improperly adjusted brakes, worn brake pads, o
r w
heels on which the rim wear mark is visible is
dangerous and can result in serious injury or death.
2. Applying brakes too hard or too suddenly can lock up a wheel, which could cause you to lose control and fall. Sudden
or excessive application of the front brake may pitch the rider over the handlebars, which may result in serious injury or
death.
3. Some bicycle brakes, such as disc brakes (fig. 11) and linear-pull brakes (fig. 12), are extremely powerful. Take extra
care in b
ecoming familiar with these brakes and exercise particular care when using them.
4. Some bicycle brakes are equipped with a brake force modulator, a small, cylindrical device through which the brake
control cable runs and which is designed t o provide a mo re progr essive application of braking force. A modulator
makes the initial brake lever force more gentle, progressively increasing force until full force is achieved. If your bike is
equipped with a brake force modulator, take extra care in becoming familiar with its performance characteristics.
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